A. Field of the Invention
The present invention relates to analyzing individual particles, such as seeds, tablets, pellets, and the like, for quantitative measure of one or more chemical components, constituents, or characteristics. One exemplary application is to agricultural seeds, such as corn and soybeans, to investigate various quality traits including, but not limited to, moisture, protein, oil, starch, amino acids, fatty acids, phytate, and other traits of interest.
B. Problems in the Art
The advantages of gaining knowledge of the chemical components or other traits of agricultural crop seed are well known and well documented. Plant breeding or plant genetic experiments use such an analysis. As such, experiments become more sophisticated, more complete and accurate information is desirable. This includes the ability to obtain information about single seeds.
One conventional evaluation technique grinds the seed up into, hopefully, a homogenous powder. Any of a variety of laboratory techniques can then be utilized to derive information about the chemical make-up of the powder. Information can be collected and used. As can be appreciated, this method is destructive of the seed. Additionally, significant time and resources are required to grind and handle individual seed and its powdered form.
Near infrared spectroscopy is a well-known science for interrogating substances for chemical makeup. It directs electromagnetic energy in the near infrared (NIR) spectrum at a specimen and detects the transmittance and/or reflectance of that energy. Evaluation of absorption of the energy reveals chemical makeup of the portion of the specimen interrogated.
Use of NIR to evaluate agricultural grain is also well known. See for example, U.S. Pat. Nos. 5,751,421; 5,991,025; and 6,483,583 to Wright et al. and incorporated by reference herein. However, those patents speak to analyzing seed or grain in bulk quantity with non-destructive NIR techniques. One example rotates a bulk sample of many seeds over an optical window. There can be agitation of the bulk sample, but not at the location of the optical window and not while taking the optical sample. The optical sampling is therefore from one plane. There is a need to analyze particles in less than bulk quantities, including individually. The main problem associated with single seed or several seeds analysis is the difficulty of complete optical interrogation of the sample. A corn kernel, for example, is very heterogeneous. That is, its major components are somewhat compartmentalized. The starch is primarily found in the endosperm, while the protein and oil are mostly contained in the germ. Manual handling of single or several seeds is not satisfactory. It is too cumbersome and time consuming, and is subject to erroneous readings. This problem has been recognized in the art and attempts have been made to solve it. Other types of seed and other types of particles can be heterogeneous.
For example, single seed analyzers utilizing NIR are commercially available. One device (Brimrose; Baltimore, Md. USA, Model # Luminaire 3076 “Seed Meister” NIR Analyzer) moves single seeds on a moving belt past an NIR transmitter. A detector captures reflectance or transmittance of the NIR energy which is then analyzed. By appropriate control, the individual seeds can be serially presented and analyzed. While this method optically samples each kernel, it does so from basically one direction (or in generally one plane), and for a limited window in time.
Another prior art method directs NIR energy into a single seed from various directions while the seed is placed or laid in a hole. This increases the number of interrogation angles, but is still generally in a single plane. The supporting structure holding the seed also blocks parts of the seed from optical interrogation, as the seed is static in the hole.
Therefore, a real need in the art exists for a method which provides a better optical sample of the whole particle under investigation in a non-destructive, efficient, economical manner.